CSAT 2021

Q. When a certain number is multiplied by 7, the product entirely comprises ones only (1111…). What is the smallest such number?

(a) 15713
(b) 15723
(c) 15783
(d) 15873
Correct Answer: (d) 15873

Question from UPSC Prelims 2021 CSAT Paper

Explanation : 

Best Method- Check All option
15873 × 7 = 111111

Check Demo Video

UPSC Factory
Conquer UPSC offline! 🚀 PYQs (Prelims & Mains), test series, syllabus tracker. Give it a try, you will love it 💯
UPSC Factory for Windows
Master UPSC offline! 📚🎯 4000+ Prelims PYQs, Mains model answers, NCERT books, Syllabus tracker, topper notes, past papers. Give it a try, you will love it !!💯
UPSC Factory App
Conquer UPSC offline! 🚀 PYQs (Prelims & Mains), test series, syllabus tracker. Focus intensely without distractions.💯